The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Digitally stored electronic maps are used to provide directions to users of mobile or onboard navigation devices, for example, using any of a wide array of standalone map or direction application programs or apps. Today's electronic maps correctly determine where a device is within a few feet or meters, or show where the user of that device is on the electronic map in real time. Electronic maps also typically include other functionality, such as providing turn-by-turn directions to nearly any location. Additional elements such as traffic or wrecks may also be shown.
Electronic maps also appear in other applications aside from standalone mapping applications. For example, ride sharing applications, taxi applications, video games, and other applications may use digital maps. These or other applications can obtain electronic maps by calling a map server computer through an Application Programming Interface (API). Thus, a single electronic map provider that owns or operates the server computer may supply the electronic maps for many different applications.
When using an electronic map, the location of a user's device can be determined using WiFi or the Global Positioning System (GPS), which reports a user's location using latitude and longitude, and optionally height and time as well. This location data, as well as other data, is collected by the electronic map provider. Despite collecting large amount of data, electronic maps are not perfect. For example, a digital map stored at the server computer may specify that a vehicle cannot turn or transition from a first road to a second road, when in fact such a turn or transition is possible at the real-world location corresponding to the mapped location. Or, the map may specify that a turn is possible, but at the real-world location the turn may be impossible due to construction, road realignment, road removal or other factors. Acquiring corrective data for such situations, in the past, has required active manual individual reports from drivers or other observers who have visited the location. These reports can be falsified, or not received soon enough to update the map with a desired degree of accuracy. Thus, improved methods for electronic mapping are needed.